Determining uplink control channel repetition factors

Abstract

Methods, systems, and devices for wireless communications are described. Generally, a base station may implicitly indicate a physical uplink control channel (PUCCH) repetition factor for a user equipment (UE) to use on a next PUCCH via the selection of an aggregation level for the preceding physical downlink control channel (PDCCH). For example, the base station may configure relationships between PUCCH repetition factors and aggregation levels. To determine which PUCCH repetition factor the UE should use, the base station may select the corresponding aggregation level, and may transmit a downlink control message (e.g., a downlink control information (DCI) message) on a PDCCH using the selected aggregation level that corresponds to the desired PUCCH repetition factor.

What is claimed is: 
     
       1. A method for wireless communications at a user equipment (UE), comprising:
 receiving a message that indicates at least one association between a bandwidth part (BWP) and a physical uplink control channel (PUCCH) repetition factor; 
 receiving downlink control information (DCI) that includes an indication for the UE to switch to the BWP for communications; 
 determining the PUCCH repetition factor based at least in part on the indication of the at least one association between the BWP and the PUCCH repetition factor; and 
 transmitting a PUCCH based at least in part on the PUCCH repetition factor. 
 
     
     
       2. The method of  claim 1 , wherein the receiving of the message that indicates the at least one association between the BWP and the PUCCH repetition factor comprises:
 receiving a semi-static configuration via radio resource control signaling that indicates the at least one association between the BWP and the PUCCH repetition factor, wherein determining the PUCCH repetition factor is based at least in part on the semi-static configuration. 
 
     
     
       3. The method of  claim 2 , wherein the semi-static configuration is a PUCCH resource set configuration. 
     
     
       4. The method of  claim 2 , wherein the semi-static configuration indicates one or more associations between possible BWPs and corresponding PUCCH repetition factors. 
     
     
       5. The method of  claim 1 , wherein the at least one association between the BWP and the PUCCH repetition factor is based at least in part on a PUCCH resource set, a PUCCH format, an uplink control information size, or uplink control information content. 
     
     
       6. The method of  claim 1 , further comprising:
 receiving a downlink medium access control (MAC) control element (MAC-CE) that indicates one or more updated associations between possible BWPs and corresponding PUCCH repetition factors. 
 
     
     
       7. The method of  claim 1 , wherein the DCI is a first DCI, and further comprising:
 receiving a second DCI that indicates one or more updated associations between possible BWPs and corresponding PUCCH repetition factors. 
 
     
     
       8. A method for wireless communications at a user equipment (UE), comprising:
 receiving first signaling indicating that a first repetition factor index is associated with a first mapping of a first quantity of physical uplink control channel (PUCCH) repetitions to a first set of transmission parameters and a second repetition factor index is associated with a second mapping of a second quantity of PUCCH repetitions to the first set of transmission parameters; 
 receiving second signaling that selects the first repetition factor index from among the first repetition factor index and the second repetition factor index indicated via the first signaling; and 
 using, based at least in part on the second signaling that selects the first repetition factor index, the first quantity of PUCCH repetitions for a first PUCCH transmission associated with the first set of transmission parameters. 
 
     
     
       9. The method of  claim 8 , further comprising:
 receiving third signaling that selects the second repetition factor index from among the first repetition factor index and the second repetition factor index indicated via the first signaling; and 
 using, based at least in part on the third signaling that selects the second repetition factor index, the second quantity of PUCCH repetitions for a second PUCCH transmission associated with the first set of transmission parameters. 
 
     
     
       10. The method of  claim 8 , further comprising:
 receiving signaling indicating the first quantity of PUCCH repetitions is associated with a second set of transmission parameters; and 
 using the first quantity of PUCCH repetitions for a second PUCCH transmission associated with the second set of transmission parameters. 
 
     
     
       11. The method of  claim 8 , wherein receiving the first signaling comprises receiving downlink control information (DCI) signaling. 
     
     
       12. The method of  claim 8 , wherein receiving the first signaling comprises receiving downlink medium access control (MAC) control element (MAC-CE) signaling. 
     
     
       13. The method of  claim 8 , wherein the first set of transmission parameters is associated with the first PUCCH transmission based on the first set of transmission parameters being associated with a physical downlink shared channel (PDSCH) transmission associated with the first PUCCH transmission. 
     
     
       14. The method of  claim 8 , wherein the first set of transmission parameters comprises a transmit beam, a bandwidth part, a content of the PUCCH transmission, a physical downlink shared channel (PDSCH) associated with the first PUCCH transmission, or a semi-persistent scheduling (SPS) transmission associated with the first PUCCH transmission. 
     
     
       15. An apparatus for wireless communications at a user equipment (UE), comprising:
 one or more processors; 
 memory coupled with the one or more processors; and 
 instructions stored in the memory and executable by the one or more processors to cause the apparatus to:
 receive a message that indicates at least one association between a bandwidth part (BWP) and a physical uplink control channel (PUCCH) repetition factor; 
 receive downlink control information (DCI) that includes an indication for the UE to switch to the BWP for communications; 
 determine the PUCCH repetition factor based at least in part on the indication of the at least one association between the BWP and the PUCCH repetition factor; and 
 transmit a PUCCH based at least in part on the PUCCH repetition factor. 
 
 
     
     
       16. The apparatus of  claim 15 , wherein the instructions to receive the message that indicates the at least one association between the BWP and the PUCCH repetition factor are further executable by the one or more processors to cause the apparatus to:
 receive a semi-static configuration via radio resource control signaling that indicates the at least one association between the BWP and the PUCCH repetition factor, wherein determining the PUCCH repetition factor comprises is based at least in part on the semi-static configuration. 
 
     
     
       17. The apparatus of  claim 16 , wherein the semi-static configuration is a PUCCH resource set configuration. 
     
     
       18. The apparatus of  claim 16 , wherein the semi-static configuration indicates one or more associations between possible BWPs and corresponding PUCCH repetition factors. 
     
     
       19. The apparatus of  claim 15 , wherein the at least one association between the BWP and the PUCCH repetition factor is based at least in part on a PUCCH resource set, a PUCCH format, an uplink control information size, or uplink control information content. 
     
     
       20. The apparatus of  claim 15 , wherein the instructions are further executable by the one or more processors to cause the apparatus to:
 receive a downlink medium access control (MAC) control element (MAC-CE) that indicates one or more updated associations between possible BWPs and corresponding PUCCH repetition factors. 
 
     
     
       21. The apparatus of  claim 15 , wherein the DCI is a first DCI, and wherein the instructions are further executable by the one or more processors to cause the apparatus to:
 receive a second DCI that indicates one or more updated associations between possible BWPs and corresponding PUCCH repetition factors. 
 
     
     
       22. An apparatus for wireless communications at a user equipment (UE), comprising:
 one or more processors; 
 memory coupled with the one or more processors; and 
 instructions stored in the memory and executable by the one or more processors to cause the apparatus to:
 receive first signaling indicating that a first repetition factor index is associated with a first mapping of a first quantity of physical uplink control channel (PUCCH) repetitions to a first set of transmission parameters and a second repetition factor index is associated with a second mapping of a second quantity of PUCCH repetitions to the first set of transmission parameters; 
 receive second signaling that selects the first repetition factor index from among the first repetition factor index and the second repetition factor index indicated via the first signaling; and 
 use, based at least in part on the second signaling that selects the first repetition factor index, the first quantity of PUCCH repetitions for a first PUCCH transmission associated with the first set of transmission parameters. 
 
 
     
     
       23. The apparatus of  claim 22 , wherein the instructions are further executable by the one or more processors to cause the apparatus to:
 receive third signaling that selects the second repetition factor index from among the first repetition factor index and the second repetition factor index indicated via the first signaling; and 
 use, based at least in part on the third signaling that selects the second repetition factor index, the second quantity of PUCCH repetitions for a second PUCCH transmission associated with the first set of transmission parameters. 
 
     
     
       24. The apparatus of  claim 22 , wherein the instructions are further executable by the one or more processors to cause the apparatus to:
 receive signaling indicating the first quantity of PUCCH repetitions is associated with a second set of transmission parameters; and 
 use the first quantity of PUCCH repetitions for a second PUCCH transmission associated with the second set of transmission parameters. 
 
     
     
       25. The apparatus of  claim 22 , wherein the instructions to receive the first signaling are executable by the one or more processors to cause the apparatus to receive downlink control information (DCI) signaling. 
     
     
       26. The apparatus of  claim 22 , wherein the instructions to receive the first signaling are executable by the one or more processors to cause the apparatus to receive downlink medium access control (MAC) control element (MAC-CE) signaling. 
     
     
       27. The apparatus of  claim 22 , wherein the first set of transmission parameters is associated with the first PUCCH transmission based on the first set of transmission parameters being associated with a physical downlink shared channel (PDSCH) transmission associated with the first PUCCH transmission. 
     
     
       28. The apparatus of  claim 22 , wherein the first set of transmission parameters comprises a transmit beam, a bandwidth part, a content of the PUCCH transmission, a physical downlink shared channel (PDSCH) associated with the first PUCCH transmission, or a semi-persistent scheduling (SPS) transmission associated with the first PUCCH transmission.